The pilot advised controllers that they had a ‘mechanical problem’ but did not declare an emergency.

It is understood that water was discovered dripping from an overhead passenger service units (PSU) and close to electrical equipment. A PSU is the panel over seat rows that contains air vents, reading lights and drop-down oxygen masks.

The Airbus A330-300 jet was about 200 kilometres off the Irish coast when cabin crew detected the problem and reported to the flight crew.

The flight turned around and routed back to Dublin where it landed normally at 2.45pm.

Last Tuesday, an Aer Lingus flight from Ireland to the US was forced to turn around over Greenland and return to Dublin.

The Airbus A330 was almost three hours into its flight to Los Angeles when the crew decided not to continue with their journey.

The flight returned to Dublin for a safe landing after suffering what the airline described as ‘technical reasons’.

Also during the week, Shannon Airport dealt with four aircraft diversions including one flight with a smoke in the cockpit; another with a cargo hold smoke warning and two medical emergencies.

The treatment trial saw participants go from allergic reactions such as immediate vomiting, swelling of the throat, blisters on tongue and stomach pain to being able to safely ingest up to four peanuts.

Part of a €20,000 award to a shopper who fell into a supermarket freezer after she had to lean in to get frozen vegetables from the bottom is to be held in a solicitor's account pending an appeal over the case, the High Court has ruled.